24-08-2010, 01:10 AM
[attachment=4116]
MOISTURE MANAGEMENT IN TEXTILES/APPARELS
BY
G.MOHAN KUMAR
V.S.SIDDARTH
BANNARI AMMAN INSTITUTE OF TECHNOLOGY
MOISTURE MANAGEMENT
The ability to absorb gaseous or liquid humidity from the skin and transport it to the outer surface and release it into the surrounding air.
LACK OF MOISTURE MANAGEMENT
In hot conditions, trapped moisture may heat up and lead to fatigue or diminished performance.
In cold conditions, trapped moisture will drop in temperature and cause chilling and hypothermia.
Excess moisture may also cause the garment to become heavy, as well as cause damage to the skin from chafing.
TRANSMISSION OF MOISTURE
Passage of water vapour through fabric structure.
Air-permeability is a good guide
Diffusion of water molecules through the fibres.
Dépendent on regain, amorphous content, pores, etc.
Wicking of liquid water away from skin.
Very dependent on surface properties of fibres and capillary structure of fabric
FACTORS AFFECTING MOISTURE MANAGEMENT
The factor which affects moisture management is absorbency.
Increases the ability for moisture to be drawn into the fabric.
It affects comfort levels.
Garment becomes saturated.
Less absorbency leads to regulate body temperature, improve muscle performance and delay exhaustion.
EFFECTIVE MOISTURE MANAGEMENT FABRICS
High-tech synthetic fabrics made from polyamide or polyester microfibers.
Lightweight.
capable of transporting moisture efficiently, and dry relatively quickly.
enhanced by using certain finishing processes, by varying the fabric or fibre construction, or by using a blend of fibre types.
DIFFERENT CONCEPTS OF MOISTURE MANAGEMENT
Combinations of inner hydrophobic and outer hydrophilic layers.
Micro fibres.
Special fibres like trilobal.
Depending on the amount of physical effort made by the athlete, and the degree of humidity released, it could make sense to combine different concepts in order to reach an optimized moisture management.
COMBINATIONS OF HYDROPHOBIC AND HYDROPHILIC LAYERS
designed to transport humidity rapidly from the skin and evaporate it on the outside.
The two-sidedness of the fabric is either attained by processing different materials during manufacturing or by varied coatings of the fabric surfaces.
MICRO FIBRES
Micro fibres, by virtue of their extreme fineness, form especially small gaps and have a big surface area.
This leads to high capillary effect for the transportation of humidity, and rapid evaporation.
SPECIAL FIBRES
Designed to increase the capillary force and the humidity transportation, by means of special profiles.
The larger surface area of these fibres also serves to promote evaporation.
Water Vapour Permeability (WVP)
The weight (g) of water vapour passing through one square metre of fabric over a period of 24 hours.
Ability to remove perspiration without affecting thermal insulation.
Particularly important for active wear.
MOISTURE MANAGEMENT TESTING
The different types of testing methods:
ASTM moisture vapour test - (open cup test)
GATS- (gravimetric absorbency test system)
Gross Absorbency Test
Moisture Management Tester
Cup weighed initially and again after period of several hours.
The temperature of the water, the air above the water and the surrounding air is the same.
The weight of water evaporated through the textile is measured after a certain time.
GROSS ABSORBENCY TEST
The sample is placed on another textile which is evenly saturated with water.
The lower textile is kept saturated by a sponge placed under it, while the sample soaks up the water and evaporates it.
MOISTURE MANAGEMENT TESTER
The sample is placed flat between two plates of different diameters with circular sensors.
After application of a special liquid, the sensors measure the changes in resistance between each upper and lower pair of sensors.
In this way:
The duration of moisture absorption,
The radius of spreading,
The speed of spreading,
The amount of moisture transported, and by this, the overall moisture management can be measured.
LACK OF A STANDARD FOR OBJECTIVE TESTING
Despite the lack of a standard for objective testing of moisture manage¬ment, there are interesting possibilities for the variation of moisture transportation and skin feeling - also and especially - with the help of a subsequent finishing of fabric.
CONCLUSION
The moisture management is a essential property for any textiles/apparels especially for sports wears.
The normal sports wears can have low moisture transfer but the active sports wear must have high moisture transfer.